DESCRIPTION: Should children presenting to the hospital with new-onset Henoch Schonlein purpura (HSP) be treated with systemic corticosteroids in order to prevent the common subsequent complications, including renal injury? A rigorous answer to this question would have substantial clinical implications. We hypothesize, as have others, that corticosteroids ameliorate inflammation, hasten the resolution of acute manifestations of HSP, and protect the kidneys from long-term injury. The proposed study will use data collected from more than 30 children's hospitals in the United States over a 4 year period. It will be the first to use propensity score matched analysis to examine the difference between patients treated either with or without steroids in rates of hospital readmission, and development of co-morbidities necessitating readmission including nephritis, hypertension, recurrent abdominal pain, and intussusception. Data from this study will clarify the effect of corticosteroids on patients hospitalized with HSP, and will inform the design of future clinical investigations. We specifically aim to: 1) Describe the prevailing clinical management of children with HSP, specifically assessing the use and timing of corticosteroid treatment for patients with different manifestations of HSP and examining the variation in the use of corticosteroids among hospitals. 2) Compare outcomes of children with HSP who receive supportive care versus corticosteroids, with adjustment (through propensity score matching) for the likelihood of having received corticosteroids. 3) Determine the short-term safety of corticosteroid treatment for children with HSP by determining the rate of corticosteroid-associated complications during the initial admission and any subsequent readmissions. Relevance: HSP is the most common vasculitis of childhood affecting approximately 8-10/100,000 children annually and accounting for 49% of all childhood vasculitides in the United States. Approximately 40% of these children require hospitalization secondary to glomerulonephritis, hypertension, intractable pain or gastointestinal bleeding. Beyond the acute phase the major morbidity is prolonged urenal disease. How best to treat the acute manifestations and prevent the long-term complications of HSP remains controversial. Improvement in therapy and prevention requires better designed retrospective studies, such as the study proposed herein, and larger prospective randomized controlled trials. Such studies may provide evidence in support of early corticosteroid treatment for HSP, or may more firmly reveal this to be an ineffective means to improve these patients' outcomes, and thus spur therapeutic research in a different direction, focusing perhaps on other immunomodulatory or renal-protective treatments. [unreadable] [unreadable] [unreadable] [unreadable]